Solid-state imaging device, analogue-digital converting method in solid-state imaging device and imaging apparatus

Abstract

The present invention provides a solid-state imaging device including: a pixel array block; a row scanning device; and an analogue-digital conversion device, the analogue-digital conversion device including: a comparing device having a reset device; a counting device that counts a comparison period from initiation to completion of comparison performed by the comparing device; and a changing device that changes a voltage at the other input terminal to a predetermined voltage after a resetting operation performed by the reset device.

1. A solid-state imaging device comprising:
 a pixel array block including unit pixels each having photoelectric conversion units two-dimensionally arranged in a row and column array and column signal lines wired for each column with respect to the row and column arrangement of the unit pixels; 
 a row scanning device that selectively controls the respective unit pixels in the pixel array block on a row-to-row basis; and 
 an analogue-digital conversion device that compares an analogue signal outputted from the unit pixel of a row which is selectively controlled by the row scanning device via the column signal line with an inclined reference signal, and converts the analogue signal into a digital signal on the basis of a comparison period; 
 the analogue-digital conversion device including: 
 a comparing device having two input terminals, a reset device that resets potentials at the two input terminals and having a configuration of a differential amplifier that compares the analogue signal applied to one of the two input terminals with a reference voltage applied to the other of the two input terminals 
 a counting device that counts a comparison period from initiation to completion of comparison performed by the comparing device; and 
 a changing device that changes a voltage at the other input terminal to a predetermined voltage after a resetting operation performed by the reset device. 
 
     
     
       2. The solid-sate imaging device according to  claim 1 , wherein the predetermined voltage is set to a voltage value that compensates a voltage difference between the two input terminals after the resetting operation performed by the reset device. 
     
     
       3. In a solid-state imaging device including: a pixel array block including unit pixels each having photoelectric conversion units two-dimensionally arranged in a matrix array and column signal lines wired for each column with respect to the matrix arrangement of the unit pixels; and a row scanning device that selectively controls the respective unit pixels in the pixel array block on a row-to-row basis;
 a driving method for the solid-state imaging device for converting an analogue signal to a digital signal using a comparing device having two input terminals, a reset device that resets potentials at the two input terminals and having a configuration of a differential amplifier that compares the analogue signal provided to one of the two input terminals via the column signal line from the unit pixel of a row selectively controlled by the row scanning device with an inclined reference signal provided to the other of the two input terminals, the method comprising the steps of: 
 changing the voltage at the other input terminal to a predetermined voltage after the resetting operation performed by the reset device; 
 counting a comparison period from initiation to completion of comparison performed by the comparing device by causing the reference signal to be inclined; and 
 converting the analogue signal to the digital signal on the basis of the comparison period. 
 
     
     
       4. An imaging apparatus comprising:
 a solid-state imaging device; and an optical system that forms an image of image light from a photographic object on an imaging plane of the solid-state imaging device, 
 the solid-state imaging device including: 
 a pixel array block including unit pixels each having photoelectric conversion units two-dimensionally arranged in a row and column array and column signal lines wired for each column with respect to the matrix arrangement of the unit pixels; 
 a row scanning device that selectively controls the respective unit pixels in the pixel array block on a row-to-row basis; 
 an analogue-digital conversion device that compares an analogue signal outputted from the unit pixel of a row which is selectively controlled by the row scanning device via the column signal line with an inclined reference signal, and converts the analogue signal into a digital signal on the basis of a comparison period; 
 the analogue-digital conversion device including: 
 a comparing device having two input terminals, a reset device that resets potentials at the two input terminals and having a configuration of a differential amplifier that compares the analogue signal applied to one of the two input terminals with a reference voltage applied to the other of the two input terminals; 
 a counting device that counts a comparison period from initiation to completion of comparison performed by the comparing device; and 
 a changing device that changes a voltage at the other input terminal to a predetermined voltage after a resetting operation performed by the reset device.